The present invention relates to a ferrule for a multi fiber optical connector and a method of manufacturing the multi fiber optical connector.
Up to now, there are a variety of ferrules for a multi fiber optical connector one of which is a ferrule for a multi fiber optical connector as shown in FIG. 8. The ferrule for a multi fiber optical connector includes an entry B into which a tape-like multi optical fiber A (hereinafter referred to as xe2x80x9cmulti fiber tape Axe2x80x9d) is insertable, a plurality of guide grooves D that guide the respective optical fibers C that makes up the multi fiber tape A inserted from the entry B, and a plurality of fiber holes E into which the respective optical fibers C guided by the guide grooves D are inserted. More specifically, as shown in FIGS. 9A to 9C, two upper and lower fiber hole arrays F where the fiber holes E are arranged in parallel lines are laminated. Each of the fiber holes E that make up the fiber hole arrays E is made up of a guide hole G that communicates with the guide groove D and a minute hole H that communicates with the guide hole G. Each of the optical fibers C of the multi fiber tape A inserted from the entry B is inserted into the corresponding guide hole G while being guided by the corresponding guide groove D and then inserted into the minute hole H while being guided by the guide hole G.
A method of manufacturing the multi fiber optical connector by fitting the ferrule for a multi fiber optical connector thus structured onto a leading end of the multi fiber tape will be described below.
(1) As shown in FIG. 9A, the multi fiber tape A inserted into the ferrule for a multi fiber optical connector from the entry B of the ferrule is inclined toward a direction indicated by an arrow in the figure. As a result, the leading end of each of the optical fibers C is lifted up as shown in FIG. 9B.
(2) In a state where the leading end of each of the optical fibers C is kept lifting up, the multi fiber tape A is jammed forward in such a manner that the leading end of each of the optical fibers C is positioned above a given one of the guide grooves D continuously disposed on the lower fiber hole array F2.
(3) The multi fiber tape A is inclined in a direction indicated by an arrow in FIG. 9B. As a result, the leading end of each of the optical fibers C is pressed against the corresponding guide groove D as shown in FIG. 9C.
(4) While the leading end of each of the optical fibers C is pressed against the corresponding guide groove D, each of the optical fibers C is jammed forward while being guided by the lower guide groove D. As a result, each of the optical fibers C is inserted into each of the lower guide holes G. Therefore, each of the optical fibers C is inserted into each of the minute holes H while being guided by the guide hole G.
(5) Another multi fiber tape not shown is inserted from the entry B, and each of the optical fibers is inserted into each of the fiber holes E that make up the upper fiber hole array F1 in the same manner as that described above.
(6) An adhesive is injected from an adhesive inlet L to fix those two multi fiber tapes to the ferrule for a multi fiber optical connector.
(7) As occasion demands, an end face K of the ferrule for a multiple fiber optical connector (FIG. 9A) is polished.
The above-described conventional ferrule for a multi fiber optical connector suffers from problems stated below.
As shown in FIG. 9C, a distance H1 of from a straight line X-X that connects middle points between the center axes of the fiber holes E that make up the upper fiber hole array F1 (FIG. 8) and the center axes of the fiber holes E that make up the lower fiber hole array F2 (FIG. 8) to an upper side N of the entry B is identical with a distance H2 of from the straight line X-X to a lower side P of the entry B. Specifically, H1=H2=1.075 mm is satisfied. Therefore, even if the leading end of each of the optical fibers C is going to be pressed against the corresponding guide groove D while the multi fiber tape A inserted from the entry B is inclined toward the upper side N of the entry B as shown in FIG. 9C, the multi fiber tape A is unavoidably abutted against the upper side N, thereby making it impossible to sufficiently incline the multi fiber tape A. Therefore, the leading end of each of the optical fibers C is insufficiently pressed against the corresponding guide grooves D. As a result, the guide grooves D cannot be sufficiently utilized, thereby making it difficult to insert the optical fibers C into the corresponding fiber holes E. This problem is particularly remarkable when the leading end of each of the optical fibers C is pressed against the corresponding one of the guide grooves D continuously disposed on the upper fiber hole array F1. Also, the problem becomes severer as the number of fiber hole arrays increases more.
According to a first aspect of the present invention, there is provided a ferrule for a multi fiber optical connector comprising: an entry into which a multi fiber tape is insertable; guide groove arrays in which a plurality of guide grooves that guide the respective optical fibers that make up the multi fiber tape inserted from the entry are arranged in plural parallel lines; and fiber hole arrays in which a plurality of fiber holes into which the respective optical fibers guided by the respective guide grooves are inserted are arranged in plural parallel lines; wherein said guide groove arrays and said fiber hole arrays are laminated at plural stages, and a distance of from a straight line that connects middle points between the center axes of the fiber holes that make up a fiber hole array at one end side in a laminating direction and the center axes of the fiber holes that make up a fiber hole array at another end side to an upper side of the entry is longer than a distance of from the straight line to a lower side of the entry.
According to another aspect of the present invention, there is provided a ferrule for a multi fiber optical connector comprising: an entry into which a multi fiber tape is insertable; guide groove arrays in which a plurality of guide grooves that guide the respective optical fibers that make up the multi fiber tape inserted from the entry are arranged in plural parallel lines; and fiber hole arrays in which a plurality of fiber holes into which the respective optical fibers guided by the respective guide grooves are inserted are arranged in plural parallel lines; wherein a ceiling of the entry is notched to form an opening so that an inclination of the multi fiber tape is not regulated by the upper side of the entry when a leading end of each of the optical fibers is pressed against the corresponding guide groove while the multi fiber tape inserted from the entry is inclined toward the upper side of the entry.
According to still another aspect of the present invention, there is provided a method of manufacturing a multi fiber optical connector comprising: an entry into which a multi fiber tape is insertable; guide groove arrays in which a plurality of guide grooves that guide the respective optical fibers that make up the multi fiber tape inserted from the entry are arranged in plural parallel lines; and fiber hole arrays in which a plurality of fiber holes into which the respective optical fibers guided by the respective guide grooves are inserted are arranged in plural parallel lines, in which a ferrule for the multi fiber optical connector having said guide groove arrays and said fiber hole arrays laminated at plural stages is fitted to the multi fiber tape; said method comprising the steps of: providing an angle between each of the optical fibers of multi fiber tape and a plane extending in the arrangement direction of said guide grooves by inclining said multi fiber tape obliquely and downward when inserting the multi fiber tape into the ferrule for the multi fiber optical connector from the entry of the ferrule.